I've watched this happen twice in the last half hour. When a zombie walked onto my property, I told the peashooter to attack it. The first time, the zombie collapsed and fell asleep after being hit about twice or three times, and there were V's over his head like a vampire as I saw the green skin vanish. So he must have been a vampire before becoming a zombie. He woke up, and walked away. The same thing happened with a zombie/fairy. He was a zombie, but had fairy wings. Again, I told the peashooter to attack him. Same thing. It hit him about three times, he appeared to faint, and then he was just a fairy. Not a zombie.
I wanna fill my yard with these things.
Edit: Well okay, it doesn't always happen. A zombie just ate my peashooter. D:
Another edit: Okay, it seems so far, that most of the time, the peashooters will de-zombify their victims. Four out of five zombies were turned. These things are nifty for getting rid of zombies. Seriously, I had FOUR on my lot at once!